Barfly
Custom User Title
You can certainly do the Bean Overflow. 3 Drains is all you will need. 2" pvc will move an extreme amount of water. For example, 2" drain pipe at 4' head height is capable of draining over 9,000gph at full siphon.
HTH
Silent and Failsafe Overflow System
- Thread starter JohnL
- Start date
You can certainly do the Bean Overflow. 3 Drains is all you will need. 2" pvc will move an extreme amount of water. For example, 2" drain pipe at 4' head height is capable of draining over 9,000gph at full siphon.
HTH
Newbie Aquarist
Reefing is my middle name
Finally thanks.
Barfly
Custom User Title
pm replied to
Howdy folks... great design for an overflow.
Anyone have experience implementing this with a fish room? My fish room is 25 feet from my display. I had a "modified durso" type dual 2 inch overflow on the tank that was originally intendeded... during testing I wasn't very happy with it.
I'm going to implement this because I like the safety.
So my questions are:
1. Should the emergency be a completely redundant line?
2. Can I come out of the siphon, go to a valve, and then tee in the open channel to that line? or does the siphon line need to be completely separate? It seems like the siphon is between the valve and the overflow and the pipe may be not completely full beyond that. However, I can't say without testing it.
3. I'm trying to avoid 3 lines out to my fish room..... could the e-flow (emergency overflow) and open channel be tied together? Any suggestions on why this should be avoided?
4. I'm pretty confident that the 2 inch line isn't going to clog..... could I marry all 3 lines south of the valve? i.e. siphon -> valve - Tee - fish room / open channel - tee / emergency - tee
5. In the sump, does the line need to be submerged to maintain the siphon effect? I'm planning to feed my refugium from the overflow (eliminates a pump in doing so).. plumbing is a bit complicated to take advantage of it.. but it should work. I could easily use the open channel to do this as the fuge needs flow, not torrent.
Anyone have experience implementing this with a fish room? My fish room is 25 feet from my display. I had a "modified durso" type dual 2 inch overflow on the tank that was originally intendeded... during testing I wasn't very happy with it.
I'm going to implement this because I like the safety.
So my questions are:
1. Should the emergency be a completely redundant line?
2. Can I come out of the siphon, go to a valve, and then tee in the open channel to that line? or does the siphon line need to be completely separate? It seems like the siphon is between the valve and the overflow and the pipe may be not completely full beyond that. However, I can't say without testing it.
3. I'm trying to avoid 3 lines out to my fish room..... could the e-flow (emergency overflow) and open channel be tied together? Any suggestions on why this should be avoided?
4. I'm pretty confident that the 2 inch line isn't going to clog..... could I marry all 3 lines south of the valve? i.e. siphon -> valve - Tee - fish room / open channel - tee / emergency - tee
5. In the sump, does the line need to be submerged to maintain the siphon effect? I'm planning to feed my refugium from the overflow (eliminates a pump in doing so).. plumbing is a bit complicated to take advantage of it.. but it should work. I could easily use the open channel to do this as the fuge needs flow, not torrent.
panther_119
New member
i want a c2c overflow box for my 72x36x27 tank. where do i go about buying/making the overflow box?
I am close to finishing my "bean" system. Couple questions...
1) What's the best way to attach my overflow box to my tank? (They are both arcylic)
2) I drilled my bulkheads all at the same level... Will I be able to get the same benefits by shortening 1 of the schedule 90's?
3) I've read a lot of people suggest using gate valves. Is this nessesary on all 3 drains? (it may be a tight fit for all those under my tank.)
4) I have also read that some suggest taking the sharp edge off the inside of the overflow box. Is this something I should do?
Thanks for all your opinions!
1) What's the best way to attach my overflow box to my tank? (They are both arcylic)
2) I drilled my bulkheads all at the same level... Will I be able to get the same benefits by shortening 1 of the schedule 90's?
3) I've read a lot of people suggest using gate valves. Is this nessesary on all 3 drains? (it may be a tight fit for all those under my tank.)
4) I have also read that some suggest taking the sharp edge off the inside of the overflow box. Is this something I should do?
Thanks for all your opinions!
machined a block of PVC held in place by the suction of the siphon
it goes full siphon faster than the 2.5" caps and grabs water lower in the c2c, but if there is a power failure, its kinda heavy, perhaps even more than mangiets could hole until the siphon restarts.
Very cool. I'd just machine a clamp out of pvc. Modified c clamp with a pad on the outside and maybe a screw with a wedge.... drive the wedge vertically up or down to increase clamping force. Could make the wedge out of something that is non-friction
You could also drill some small holes in the glass and machine a flange for the outside of the glass then just use fasteners to clamp around the glass. Your primary goal is to keep force on the o-rings if I see the system right.
crossleymarko
New member
ok all set up... heres my problem.. i have full syphon on 1 pipe but the partial syphon is way too loud how vcan i cure this... i have i ball valve on full syphon.. fully open.
thanks..
thanks..
Can you give some pipe sizes and estimated flow rates?
You may need another pipe.... hard to say without more info.
crossleymarko
New member
3 x 21.5mm bulkheads.
full syphon is 1.5" with a ball valve. near sump
emergency is 1 1/4" also partial syphon. no ball valves.
pump is halea 5000ltr
full syphon is 1.5" with a ball valve. near sump
emergency is 1 1/4" also partial syphon. no ball valves.
pump is halea 5000ltr
crossleymarko
New member
just to add, the c2c empties and gives a gurgle... it does this repeatedly... is my pump not pushing as much as it should.. its as if theres too much syphon.. but as soon as i turn the valve around half to slow it down i get bubbles...
and noise..
arrrgghhhh
and noise..
arrrgghhhh
I posted some calculators just now...
http://www.reefcentral.com/forums/showthread.php?t=2086085
However, you could lower your siphon intake or raise your open channel and emergency..... this would create more head and your siphon would pull more...
My guess is that the bulkheads are your limiting factor...
based on playing with the numbers.... I think you are running 75% through your siphon and 25% through your open channel.
Your emergency cannot handle your entire flow. It's nice that you have a 1.25" opening, but the 21.5mm bulkhead is .84 inches in diameter.... and that's the limit.
I would install a second siphon and a much larger emergency.
I think you are running about 4 feet of drop from your overflow to your sump.
A 1.25" bulkhead (with a 1.25" opening) can handle 36.8 gallons per minute in your system. Your pump delivers about 22.01 gpm flow converter
I would install a 2" bulkhead if space permits.. a 2 inch bulkhead will flow 94.29 gallons per minute which will handle anything you can throw at it including a minor obstruction.
http://www.reefcentral.com/forums/showthread.php?t=2086085
However, you could lower your siphon intake or raise your open channel and emergency..... this would create more head and your siphon would pull more...
My guess is that the bulkheads are your limiting factor...
based on playing with the numbers.... I think you are running 75% through your siphon and 25% through your open channel.
Your emergency cannot handle your entire flow. It's nice that you have a 1.25" opening, but the 21.5mm bulkhead is .84 inches in diameter.... and that's the limit.
I would install a second siphon and a much larger emergency.
I think you are running about 4 feet of drop from your overflow to your sump.
A 1.25" bulkhead (with a 1.25" opening) can handle 36.8 gallons per minute in your system. Your pump delivers about 22.01 gpm flow converter
I would install a 2" bulkhead if space permits.. a 2 inch bulkhead will flow 94.29 gallons per minute which will handle anything you can throw at it including a minor obstruction.
In addition would 1/4" be enough clearance from the top of my overflow and the top of my tank?
crossleymarko
New member
i asked bean animal in an earlier post if 21.5mm is acceptable and it was a yes... if anything im pulling too much and the syphon empties the overflow box
Okay... and I think Bean has made a fantastic contribution so I don't want him or anyone else to take this as me throwing stones.....
*BUT*
You told me you have a drain with a 21.5mm diameter.... and I'm assuming that you are running about 4 feet of head.
If you know the exact output of your pump we can work backwards.... yes, it's rated at 5000/lph, but it will have flow loss between the pump outlet and the tank. If it's a reputable manufacturer, they will publish a table for the pump that states for X consumption of amps you are at Y feet in head. If you find this chart and measure your consumption it is a cheap and easy way to determine your delivered flow.
Now, back to your issue... you are telling us that you have the siphon wide open. Right? You are also saying the open circuit is too loud.
If the siphon is running at 100% (valve wide open) and the open circuit is making noise, it means the OC is handling enough of a load to become a durso type drain and it's creating a vortex, which in turn makes noise.
The Open Circuit should be silent if it is handling a minor amount of flow..... if I understand things right the idea is that your open circuit balances your siphon..... and you direct a little through the open circuit and the bulk through the siphon.
Now, the orifice flow calculator is based on hard physics and engineering data that is pretty well researched. The only real variable is how much head your system presents to the orifice (pipe). I *think* you would measure the distance from the tank surface at the overflow to the sump surface and that is roughly your head, less any restrictions.
I'm out of my league in sharp-shooting the engineering.... I have no idea what the orifice co-efficient is - so I left it at .60. That suggests 40% drag which sounds fine.
The world of plumbing works off these calculations, so I trust them more than opinions of hobbyists... no disrespect intended.....
When I convert 21.5mm to inches it tells me that your pipe is not capable of handling the flow needed in a full emergency (both pipes blocked). Now, if you get away with it.... well, congratulations. The odds of a full blockage on 2 pipes... well buy a lottery ticket first.... but an emergency system should be capable of handling a substantial amount of load.
There is a fast way to test this. Plug your siphon and see what happens. Then plug or partially plug your open circuit. If you are right, you will have no issues. If the orifice calculator is right, your tank will overflow in under one minute.
I think that if your siphon is loaded at 100% and your open circuit is making noise, it suggests too much capacity going through the OC. The only solution is to enlarge the pipe.
If it were me, I'd see if you could change bulkhead types to get a bigger orifice. 1.5 or 1.25 to .84 is a pretty hefty restriction.
Assuming 4 feet of head and the default coefficient.....
.84 delivers 16.613 gallons per minute.
1 inch delivers 23.797 gpm
1.25 inch orifice delivers 36.818 gpm... over 100% increase.
A 1.5 inch orifice delivers 53.88 GPM....
I think the calculator is right.
5000/lph is 22 gpm (assuming no losses for our conversation and debate)
if the siphon is running at 100% that would send 5.4 gpm give or take to the open channel which is about 40% and would probably induce a vortex and start sucking air.
Which leads me to an interesting question... is it really the siphon, or is the siphon simply a known capacity drain running 85% of the tank capacity..... because the siphon should act like a drain in a tank....at least through the valve......and a full pipe does indeed move more air.
I don't understand fluid dynamics well enough to answer that one... The key to vortex prevention is keeping the water level high enough to prevent entrainment of air.
Hmm, tempting tangent... anyhow, I think the flow rate calculator suggests that your bulkheads are too small.... that's my answer and I'm sticking to it Alex... :lol2:
Here is a link to a discussion about anti-vortex setups....
http://www.gouldspumps.com/pag_0006.html
In particular, there is a formula for calculating the submerged height needed to prevent a vortex.
For a 1 inch pipe, it's flow x .4085 which in the 22 gpm example is about 9 inches above the pipe is needed to prevent a vortex from forming... In a nutshell, aquarium sumps are not designed like this, so we get vortexes.
Interestingly, larger pipes require less distance. a 2 inch pipe only needs 3 inches of separation at 25gpm.
http://www.gouldspumps.com/pag_0006.html
In particular, there is a formula for calculating the submerged height needed to prevent a vortex.
For a 1 inch pipe, it's flow x .4085 which in the 22 gpm example is about 9 inches above the pipe is needed to prevent a vortex from forming... In a nutshell, aquarium sumps are not designed like this, so we get vortexes.
Interestingly, larger pipes require less distance. a 2 inch pipe only needs 3 inches of separation at 25gpm.
crossleymarko
New member
thankyou, for your time.. hotpup. what if i swapt the full syphon (1.5") to the OC tube..
i know im limited.. here in the uk we are limited to domestic plummbing parts..
ie 21.5mm overflow bulkheads.
why is the syphon emptying out the overflow box...
and why when i dial down the full syphon ball valve do i get air bubbles..
thanks
i know im limited.. here in the uk we are limited to domestic plummbing parts..
ie 21.5mm overflow bulkheads.
why is the syphon emptying out the overflow box...
and why when i dial down the full syphon ball valve do i get air bubbles..
thanks
Last edited:
BeanAnimal
Premium Member
Hotpuppy:
Respectfully, you are making this much more complicated than it needs be. You may want to note that the calculator posted on my site clearly statest that it is a straight adpatpation of the Bernoulli equation without addition of any coefficient for drag based on turbulance, friction, etc. The calculator is simply to be used as a starting point for sytstem design. Anything more complicated will account for some variables and leave others out, creating confusion and questions that I don't have the time or energy to answer. I think I pointed out there (and here in the thread many times) that the resulting flow figure should be reduced by 15% - 30% or so based on common sense regarding the plumbing topology in order to give a better real world indication of flow in the proposed system.
Crossley: (if I remember) I said something to the effect that the proposed pipe would be on the small side, but in the ballpark based on your indicated flow and other criteria you posted. If large amounts of air are coming from the open channel, then there is too much flow going through it. If (as Hotpuppy also points out) the siphon valve is wide open, then you are pushing the limits of the system. If the air is coming from the siphon standpipe, then you have other issues.
If you do have the siphon standpipe wide open and the open channel is making noise, then it is likely in two phase flow. You may be able to get it to flow open by canting it to the side a few degrees to get the water to run down one wall.
Looking at your photos, your pipe fittings look EXTREMELY restricted and I would be willing to be that the ID of those fittings is only a fraction of the listed pipe size. Are you using the ID or OD of the pipe in the calculator? It needs to be the ID of the most restrictive part of the standpipe (likely in your case the fitting from the bulkhead to the Tee).
Respectfully, you are making this much more complicated than it needs be. You may want to note that the calculator posted on my site clearly statest that it is a straight adpatpation of the Bernoulli equation without addition of any coefficient for drag based on turbulance, friction, etc. The calculator is simply to be used as a starting point for sytstem design. Anything more complicated will account for some variables and leave others out, creating confusion and questions that I don't have the time or energy to answer. I think I pointed out there (and here in the thread many times) that the resulting flow figure should be reduced by 15% - 30% or so based on common sense regarding the plumbing topology in order to give a better real world indication of flow in the proposed system.
Crossley: (if I remember) I said something to the effect that the proposed pipe would be on the small side, but in the ballpark based on your indicated flow and other criteria you posted. If large amounts of air are coming from the open channel, then there is too much flow going through it. If (as Hotpuppy also points out) the siphon valve is wide open, then you are pushing the limits of the system. If the air is coming from the siphon standpipe, then you have other issues.
If you do have the siphon standpipe wide open and the open channel is making noise, then it is likely in two phase flow. You may be able to get it to flow open by canting it to the side a few degrees to get the water to run down one wall.
Looking at your photos, your pipe fittings look EXTREMELY restricted and I would be willing to be that the ID of those fittings is only a fraction of the listed pipe size. Are you using the ID or OD of the pipe in the calculator? It needs to be the ID of the most restrictive part of the standpipe (likely in your case the fitting from the bulkhead to the Tee).
BA: Wasn't aware of your site.... I just happened to be trying to calculate Weir sizing today..... and orifice flow is a complementary equation.
I have not had a moment to read the entire thread or it's predecessor. Crossley..... I may have missed something....
Is it A or B?
A: The system is running and the siphon kicks in and empties the overflow, followed by the OC gurgling, and the siphon kicking in?
B: The siphon is running hard at full throttle and the OC is gurgling and this is stable for extended periods of time?
A: means your siphon is kicking in and out and needs to be throttled down. The siphon should only carry maybe 85% or so of the load. I'll defer to others here as I may not completely understand this design.
B: Means your siphon is doing it's thing and there is still too much capacity for the OC.... so you need either more siphon or less flow. Either increase your pipe capacity.... or add another siphon. I still think you need to test your emergency pipe and be aware that it may be limited in a worst case situation.
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